1. Field of Invention
The invention relates to a cutoff/milling device with a motor-driven cutoff/milling element, a work support surface, and a light projection device, the light projection device projecting a light beam onto a workpiece which is located on the work support surface such that the light beam marks the cutting/milling position or cutting/milling path on the workpiece and the light projection device having a switch for activation of the light projection. The invention also relates to cutoff/milling device with a motor-driven cutoff/milling element, a guide surface, and a light projection device, the light projection device projecting a light beam onto a workpiece which is located underneath the guide surface such that the light beam marks the cutting/milling position or cutting/milling path on the workpiece and the light projection device having a switch for activation of the light projection device.
2. Description of the Related Art
Cutoff/milling devices are devices which are used for working of materials, especially for cutting off and/or milling the material to be worked. Special applications for a cutoff/milling device include woodworking, working of plastics, and metalworking. However, such a device can also be used in other areas. Cutoff/milling devices are defined especially as chopsaws, band saws, circular saws, especially circular table saws, saber saws, millers and abrasive cutting machines.
A chop and miter saw known from the prior art (U.S. Patent Application Publication 2004/0182215 A1) has a motor-driven saw blade, a work support surface, and a light projection device. The light projection device projects a light beam onto a workpiece which is located on the work support surface for sawing. The light beam is projected onto the workpiece when the saw blade is still in its rest position, therefore has not yet been swung into the sawing position. The light beam thus marks the cutting position or cutting path on the workpiece, depending on whether the light beam marks essentially one point or a line of the workpiece. The light projection device in this chop and miter saw is located on the holder of the saw assembly or on a section of a handle.
In one alternative configuration of the chop and miter saw, the light projection device is used not only to mark the cutting path on the workpiece, but also the cut width of the saw blade (U.S. Patent Application Publication 2003/0233921 A1). This is done by the light projection device projecting two light beams which are spaced apart from one another onto the workpiece.
Providing a light projection device for a circular saw or a band saw (German Utility Models DE 296 16 604 U1 and DE 203 02 813 U1) is also known from the prior art. In the circular saw of German Utility Model DE 296 16 604 U1, the light projection device is located on a protective hood which surrounds the saw blade. The light projection device has its own power supply unit with batteries which is independent of the grid. Accordingly, the projection device here has its own switch for turning it on. Thus, there is the danger that, after a sawing process, turning off of the light projection device is forgotten so that the batteries are unnecessarily discharged.
Light projection devices of the type under consideration are also suited for use in cutoff/milling devices which can be placed from overhead on the workpiece to be worked, therefore manual circular saws, saber saws, or the like which have been known for decades in a host of embodiments (German Utility Model DE 90 10 761 U1).
The prior art (U.S. Patent Application Publication 2004/008369 A1) which forms the starting point of this invention discloses a chop and miter saw in which the light projection device is activated by means of a switch which reacts to motion of the saw blade, therefore the running of the machine. For this reason, the switch is made with a motion sensor. Activation of the light projection device presupposes the start of machine operation.
Other types of switches or sensors for detection of machine operation for activation of the light projection device are known from other known cutoff/milling devices (German Patent DE 102 15 871 C1, German Utility Model DE 201 20 529 U1, U.S. Patent Application Publication 2002/0131267 A1, U.S. Pat. No. 6,035,757).